Basically, anti-reflective coating works to reduce reflection or eliminate glare by applying it on the surface of lenses and other optical objects. It allows more light to pass through the lenses to give a much clearer and more enhanced vision possible.
How are We Able to See Objects?
When looking at an object, what is perceived by our eyes is the light that is reflected by the object itself. That is the reason why it is not possible for us to see things in the absence of light. As the light enters the eye, it goes through the cornea and hits a specific spot at the back of your eye, which is the retina. If you are having problems with your vision and need glasses to see clearly, it is because the light is not exactly hitting the retina of your eyes, either your eye may be too short (hyperopia) or too long (myopia), or your cornea is not in the correct form (astigmatism).
Anti-Reflective Coating on Corrective Lenses and Its Benefits
Anti-reflective coatings are widely used in different applications like on camera lens, solar lens, telescopes, and corrective lenses. More often than not, optometrists prescribe “anti-reflective lenses” to their patients for the reduced reflection makes them look better. These lenses decrease glare, but the reduction is very minimal. However, since it allows slight more light to go through, a considerable increase in visual acuity and contrast is produced. The lenses will look nearly invisible too, which draws more attention to your eyes and helps you have a better eye-contact with others.
Other benefits of this type of lenses include a sharper vision with less glare, especially when you are driving at night. They also provide greater comfort when you are using a computer for a long time. It is to be noted though, to avoid confusion, that when we say anti-reflective, it refers to the reflection coming from the surface of the lens itself. It is not the source of the light that reached the lens. There are many varieties of anti-reflection lenses these days that have additional coating, which make them water or grease resistant. This also makes the lenses much easier to clean.
How the Coating is Applied?
A highly technical procedure is needed in order to apply anti-reflective coating to lenses. It actually involves vacuum deposition technology. A productions line is usually a series of washing and rinsing baths, which includes ultrasonic cleaning to eliminate any traces of contaminants on the surface. Air drying and heating of the lenses follow to remove moisture and gases. It is then placed inside the coating chamber that is sealed and air pumped out to create vacuum. Then, the coating materials are bombarded with electrons to create a uniform and ultra thin optical layer on the lens.